Abstract:Óxido de zinco dopado com gálio (ZnO:Ga) foi preparado pelo método Pechini a partir de citrato de zinco e hidróxido de gálio. Utilizsando este método, foi possível obter ZnO:Ga cristalino pela calcinação do precursor polimérico em ar a 900ºC por 4 horas. A resina homogênea contendo 2% de dopante só pôde ser obtida com a adição de ácido etilenodiaminotetracético (edta). A adição do edta, também, ocasionou a diminuição de tamanho de partícula do óxido.
“…For the ZnO thin film, the stretching modes of Zn-O at 428 and 572 cm −1 were observed [14][15][16]. At 677 cm −1 , the COO-bond related to the overlapping of σ and π of the ligand was found [17,18]. Finally, symmetric (1421 cm −1 ) and asymmetric (1531 cm −1 ) C-O bonds and O-H groups were observed at 1636 cm −1 [14,19].…”
In this work, zinc oxide and indium-doped zinc oxide thin films at different concentrations were deposited by solution techniques at 200 °C. The thin films were characterized by XRD, Raman, FTIR and the four-point probe technique. Through FTIR spectroscopy, interesting behavior was observed when the IZO film at 6 wt.% doping showed a lower number of organic residues. Due to an inductive effect, an unusual displacement of bonds was observed. The reduction of organic residuals corroborated with the behavior of flexible metal–insulator–semiconductor (MIS) capacitors.
“…For the ZnO thin film, the stretching modes of Zn-O at 428 and 572 cm −1 were observed [14][15][16]. At 677 cm −1 , the COO-bond related to the overlapping of σ and π of the ligand was found [17,18]. Finally, symmetric (1421 cm −1 ) and asymmetric (1531 cm −1 ) C-O bonds and O-H groups were observed at 1636 cm −1 [14,19].…”
In this work, zinc oxide and indium-doped zinc oxide thin films at different concentrations were deposited by solution techniques at 200 °C. The thin films were characterized by XRD, Raman, FTIR and the four-point probe technique. Through FTIR spectroscopy, interesting behavior was observed when the IZO film at 6 wt.% doping showed a lower number of organic residues. Due to an inductive effect, an unusual displacement of bonds was observed. The reduction of organic residuals corroborated with the behavior of flexible metal–insulator–semiconductor (MIS) capacitors.
“…ZnO NPs can be obtained with different grain sizes depending on the method of synthesis. Some methods used are: electroplating [13][14][15][16][17], hydrothermal [18][19][20], sonochemical [21], sol-gel [22][23][24], Pechini [25][26][27][28][29], spray pyrolysis [3], wet chemical [30] and zinc-air system [31]. For this research, the chosen synthesis methodology was the Pechini Method (PM), due to the possibility of producing nanoparticles with good homogeneity, optical and structural characteristic, inexpensive reagents, moderate temperatures and easy process control.…”
This research aimed to build hybrid solar cells, based on Grätzel method. We used the Polyethylene Terephthalate (PET) polymer as a substrate containing a layer of Indium Tin Oxide (ITO). Films of ZnO nanoparticles (ZnO NPs) synthesized by Pechini Method, and four different dyes were tested: Congo Red (CR), Bromocresol Green (BG), Acridine Orange (AO) and a Ruthenium Complex (RC). ZnO NPs were analyzed by XRD, which generated peaks corresponding to hexagonal wurtzite crystalline structure. We also conducted analysis by UV-Vis. Spectroscopy and Transmission Electron Microscope (TEM). Rietveld analysis determined the crystal size of 115.23 ± 28.16 nm. The deposition of ZnO and dye thin films were made through spin-coating. The electrical properties of the formed films were characterized with Van der Pawn method. Efficiency in converting light in electricity under an OSRAM 20W light bulb was tested after the devices were built. The smaller sheet resistance results were obtained for material containing: PET/ITO/ZnO/CR and PET/ITO/ZnO/AO. As expected, the best open-circuit voltage (Voc) results reached were 64 and 73 mV to CR and AO, respectively. Therefore, the results demonstrated satisfactory interaction between the ZnO-Dye-Electrolyte layers.
“…Zinc oxide (ZnO) is an inorganic semiconductor compound extensively used in several materials and products including: plastic, ceramic, glass, cement, rubber, lubricant and photo-electrovoltaic devices including also the medical area [1][2][3][4][5][6][7][8][9][10][11][12][13]. For this reason, there is a great demand for new information for scrutiny about this material formed from synthesis methods and analyzed through its optical, electrical and morphological characteristics.…”
Section: Introductionmentioning
confidence: 99%
“…New methods of synthesis could lead to obtaining ZnO NPs with different grain sizes. In the preparation of ZnO some techniques are included as: Pechini [1][2][3][4][5][6], wet chemical [7], Sol-Gel [18][19][20][21][22][23], electroplating [24][25][26][27], sonochemical [28], hydrothermal [29][30][31], zinc-air system[32] and spray pyrolysis [33].…”
Zinc oxide (ZnO) nanoparticles (NPs) were synthesized by different methods known as Pechini and Sol-Gel. It was observed during the experiments significant differences comparing these methods as: particle size, time applied, crystallinity and chemical residues generated by-products. The NPs were analysed by X-ray diffraction (XRD), ultraviolet-visible (UV-Vis.) absorption and Raman spectroscopy techniques. X-Ray Difractograms showed peaks corresponding to hexagonal wurtzite crystalline structure. It was observed that NPs obtained by the Pechini showed better homogeneity and crystallinity; these presented average size of 115 nm. The NPs produced by Sol-Gel method showed crystallites with smaller average size of 8 nm. The band gap energy (Eg) obtained using UV-Vis for ZnO NPs synthesized by Pechini was 3.39 eV. Still, the results for Sol-Gel method with 5 and 10 hours of reactions were 3.53 eV and 3.55 eV respectively. Raman data obtained by Pechini and Sol-Gel Methods showed characteristics peaks. The obtained data confirmed the ZnO phase samples and the proportional relationship to the enlargement with the intensity of peaks E 2 High ˜ 438 cm -1 , as evidenced by literature. These results lead to the applicability of both NPs in optoelectronic and fluorescent applications.
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